Zebrafish Chemical Screening Reveals the Impairment of Dopaminergic Neuronal Survival by Cardiac Glycosides

Abstract

Parkinson's disease is a neurodegenerative disorder characterized by the prominent degeneration of dopaminergic (DA) neurons among other cell types. Here we report a first chemical screen of over 5,000 compounds in zebrafish, aimed at identifying small molecule modulators of DA neuron development or survival. We find that Neriifolin, a member of the cardiac glycoside family of compounds, impairs survival but not differentiation of both zebrafish and mammalian DA neurons. Cardiac glycosides are inhibitors of Na+/K+ ATPase activity and widely used for treating heart disorders. Our data suggest that Neriifolin impairs DA neuronal survival by targeting the neuronal enriched Na+/K+ ATPase α3 subunit (ATP1A3). Modulation of ionic homeostasis, knockdown of p53, or treatment with antioxidants protects DA neurons from Neriifolin-induced death. These results reveal a previously unknown effect of cardiac glycosides on DA neuronal survival and suggest that it is mediated through ATP1A3 inhibition, oxidative stress, and p53. They also elucidate potential approaches for counteracting the neurotoxicity of this valuable class of medications.

α3Na+/K+-ATPase Deficiency Causes Brain Ventricle Dilation and Abrupt Embryonic Motility in Zebrafish

“…We detected Atp1a3a expression in zebrafish TH-positive cells. In line with this, a recent study identified Atp1a3a as a target of a cardiac glycoside (a Na ϩ /K ϩ -ATPase inhibitor; Neriifolin), which impairs DA neuronal survival (60). However, our results show that Atp1a3a KD does not result in loss of DA neurons in zebrafish, although we did observe reorganization in the DA neuron distribution profile.…”

Analysis of Oxidative Stress in Zebrafish Embryos

“…A recent chemical screening of small molecules performed in zebrafish identified antioxidants as modulators of dopaminergic neurons survival, which is severely affected in mammalian neurodegenerative diseases such as Parkinson's disease 53 . This method can be used to screen for new pro-or anti-oxidant molecules in vivo.…”

Zebrafish as a Model for Developmental Neurotoxicity Assessment: The Application of the Zebrafish in Defining the Effects of Arsenic, Methylmercury, or Lead on Early Neurodevelopment

“…The zebrafish model allows screening of multiple chemical DNT within a few days through examination of cellular (apoptosis) or specific neuronal proliferation (neuronal development or survival) appearing in the brain region by utilizing simple staining methods such as acridine orange (AO) staining or immunostaining [60,61]. For example, Ton et al [61] suggested the zebrafish as a screening tool for DNT assessment, showing that measurement of cell death in the brain can be a useful endpoint using the zebrafish in the early life stage (96 hpf).…”